This is a revision of our competing renewal application, "UCLA/USC Cancer Epidemiology Training Program" (T32CA09142-21). In this revision, Dr. Detels has transferred the directorship to Dr. Zuo-Feng Zhang, a cancer molecular epidemiologist and a new faculty member in the UCLA Department of Epidemiology. The program has been re-designed to emphasize a multi-disciplinary approach to genetic molecular epidemiology of cancer to respond to the PA-97-071. In addition to population-based cancer epidemiologic studies, the new directors of this program include (1) theoretical and methodological research on genetic epidemiology, (2) natural history of cancer in genetically susceptible family members from the high genetic risk registry, and translational clinical genetic studies in high risk population; (3) tumor susceptibility genes, tumor suppressor genes, and gene-environment interaction. The existing genetic molecular laboratory components at both UCLA and USC will facilitate the training program. The faculty includes outstanding researchers from different fields such as epidemiologic methodology, biostatistics, molecular biology, human genetics, psychology, pathology, health education, and clinical sciences. All have funded cancer-related grants which provide research opportunities for trainee. The relevant resources include the USC Cancer Surveillance programs, the UCLA Tumor Registry, the High Risk Registries for cancer family members, patient population in the UCLA Medical Center, and Molecular, genetic, nutritional, and pathological laboratories within the UCLA Jonsson and USC Comprehensive Cancer Centers. The UCLA/USC Cancer Epidemiology Training Program has provided outstanding training with rigorous interdisciplinary approach in epidemiology, statistics and biology since 1975. The program provides both formal course work, primarily at UCLA, and research experience in cancer at both UCLA and USC. Graduates of the program currently hold academic positions at leading research institutions, such as Howard University, UCLA, UCSD, the University of Southern California, the University of North Carolina, the University of Washington, the University of Pennsylvania, and the Western Reserve School of Medicine.